Skhodnya, Khvalynsk, Satanay, and Podkumok calvariae: possible Upper Paleolithic hominins from European Russia

European Russia has been at the fringe of the hominin dispersal for most of the late Pleistocene. However, by about 20,000 BP this area was settled by modern humans who had highly sophisticated and sometimes unique technologies. Not many Upper Paleolithic human fossils have been described from this area and consequently the morphology of these people remains largely unknown. Here, we present descriptions and a comparative morphological analysis of four possibly late Pleistocene fossils from European Russia: Skhodnya, Khvalynsk, Satanay, and Podkumok. The frontal bone is chosen for study because it is preserved in all of these fossils and is known to provide good discrimination among groups of Pleistocene hominins. All four fossils have been previously claimed to possess 'archaic' features of frontal morphology, such as developed supraorbital relief and a flat frontal squama. The results of a 3D geometric morphometric analysis of frontal bone landmarks and semilandmarks indicate that these fossils indisputably belong to modern humans. However, there are good reasons to associate Khvalynsk, Skhodnya, and Podkumok with Upper Paleolithic fossils from central and western Europe, whereas Satanay is more similar to a pooled sample of recent modern humans.